For cream puffs:

Preheat oven to 375°F. Line 2 large baking sheets with parchment paper. Combine first 5 ingredients in heavy medium saucepan. Bring to boil, whisking until sugar dissolves and butter melts. Remove from heat. Add flour and cocoa all at once; whisk until smooth and blended (dough will form ball). Stir over low heat until dough leaves film on pan bottom, about 2 minutes. Transfer dough to large bowl; cool to lukewarm, about 8 minutes. Using electric mixer, beat in eggs 1 at a time.

Drop batter by teaspoonfuls onto prepared baking sheets in at least 64 scant 1-inch mounds. Using moistened fingertips, smooth any pointed tips on mounds. Bake puffs 20 minutes. Reduce heat to 350°F. Continue to bake until puffs are firm and beginning to crack and dry on top, about 23 minutes longer. Transfer puffs to rack. Using small knife or chopstick, poke hole in side of each puff near bottom to allow steam to escape. Cool puffs completely.

Spoon pastry cream into pastry bag fitted with 1/4-inch plain round tip. Pipe into each puff through hole in side.

For glaze:

Place 10 ounces chocolate in small microwave-safe dish. Microwave on high for 15-second intervals until beginning to melt; stir glaze until completely melted and smooth.

Dip bottom of 4 filled cream puffs into glaze. Arrange puffs, spaced about 1/4 inch apart, in square on plate. Dip bottom of 3 more puffs into glaze. Arrange in triangle atop first 4 puffs, pressing slightly so glaze holds puffs in place. Dip bottom of 1 more puff into glaze; place on top. Drizzle mound of puffs with some of glaze. Repeat with remaining cream puffs, forming 8 desserts. Refrigerate until glaze sets and holds puffs together, at least 1 hour and up to 1 day.